@PeacemakerJack noting your reference to that drive belt IDLER PULLEY , known for lubrication failure , referral to belt bounce is typically incremental bearing lube hang up . causing stop / start bounce , have made a point of enhancing all of my idler pulleys , with similar / yet different pulley , allowing a wide grease shield bearing , hi temp polyurea grease , eliminates belt bounce , might also consider , adding some vent slotting on your drive belt guard , local , metal shop , can easily punch in what ever set up you want , bring over the guard , and ask , pete